CarlB
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After the pion, the next most basic meson is the rho. There are 5 rho resonances, the rho(770), rho(1450), rho(1700), rho(1900), and rho(2150). The last two are "omitted from the summary section" by the Particle Data Group. The lower three can be put into Koide form as follows:
\lambda_{\rho n} = 25.0544\sqrt{\textrm{MeV}}(10/7 -1/3 \cos(2/9 + 2n\pi/3)\;)
This is fairly similar to the formula for the pion:
\lambda_{\pi n} = 25.0544\sqrt{\textrm{MeV}}(6/5 -3/4 \cos(2/9 + 2n\pi/3)\;)
And of course the Koide formula uses the same angle 2/9.
I don't feel very comfortable about the rational values of the v = 10/7, 6/5, and s= 1/3 and 3/4 numbers. I feel better about the fact that v+s/2 tends to be constant when you are looking at two different resonance series. That is, 10/7 + (1/3)/2 is about equal to 6/5 + (3/4)/2 to 1%. There's a good example of this 2 to 1 ratio in some of the longer resonance series where you have more terms in the series.
The reason I like this 2 to 1 relationship between v and s is because in the derivation of the previous post, it comes up with v + 2 s \cos(\delta + 2n\pi/3), so changing v and s by 2 to 1 means that the vector length is split between the constant part (the valence part) "v", and the variable or sea part "s".
I'm still thinking on Hans' equation. The kind of thing I'm looking at is geometric as in:
http://www.sparknotes.com/math/geometry2/theorems/section5.rhtml
\lambda_{\rho n} = 25.0544\sqrt{\textrm{MeV}}(10/7 -1/3 \cos(2/9 + 2n\pi/3)\;)
This is fairly similar to the formula for the pion:
\lambda_{\pi n} = 25.0544\sqrt{\textrm{MeV}}(6/5 -3/4 \cos(2/9 + 2n\pi/3)\;)
And of course the Koide formula uses the same angle 2/9.
I don't feel very comfortable about the rational values of the v = 10/7, 6/5, and s= 1/3 and 3/4 numbers. I feel better about the fact that v+s/2 tends to be constant when you are looking at two different resonance series. That is, 10/7 + (1/3)/2 is about equal to 6/5 + (3/4)/2 to 1%. There's a good example of this 2 to 1 ratio in some of the longer resonance series where you have more terms in the series.
The reason I like this 2 to 1 relationship between v and s is because in the derivation of the previous post, it comes up with v + 2 s \cos(\delta + 2n\pi/3), so changing v and s by 2 to 1 means that the vector length is split between the constant part (the valence part) "v", and the variable or sea part "s".
I'm still thinking on Hans' equation. The kind of thing I'm looking at is geometric as in:
http://www.sparknotes.com/math/geometry2/theorems/section5.rhtml
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